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Differential D19635

LTO: Don't bother trying to mangle unnamed globals, as they can't be preserved with MustPreserveSymbols.
ClosedPublic

Authored by pcc on Apr 27 2016, 3:23 PM.

Details

Reviewers
mehdi_amini
Commits
rGedf843248093: LTO: Don't bother trying to mangle unnamed globals, as they can't be preserved…
rL267820: LTO: Don't bother trying to mangle unnamed globals, as they can't be…
Summary

Should fix sanitizer-windows bot.

Diff Detail

Event Timeline

pcc updated this revision to Diff 55341.Apr 27 2016, 3:23 PM
pcc retitled this revision from to LTO: Don't bother trying to mangle unnamed globals, as they can't be preserved with MustPreserveSymbols..
pcc updated this object.
pcc added a reviewer: mehdi_amini.
pcc added a subscriber: llvm-commits.
Herald added a subscriber: mehdi_amini. · View Herald TranscriptApr 27 2016, 3:23 PM
mehdi_amini accepted this revision.Apr 27 2016, 4:52 PM
mehdi_amini edited edge metadata.

LGTM thanks!

This revision is now accepted and ready to land.Apr 27 2016, 4:52 PM
Closed by commit rL267820: LTO: Don't bother trying to mangle unnamed globals, as they can't be… (authored by pcc). · Explain WhyApr 27 2016, 4:54 PM
This revision was automatically updated to reflect the committed changes.

Revision Contents

PathSize
lib/
LTO/
4 lines
test/
LTO/
X86/
10 lines

Diff 55341

lib/LTO/LTOCodeGenerator.cpp

Show First 20 Lines • Show All 375 Lines • ▼ Show 20 Lines
void LTOCodeGenerator::applyScopeRestrictions() { void LTOCodeGenerator::applyScopeRestrictions() {
if (ScopeRestrictionsDone) if (ScopeRestrictionsDone)
return; return;
// Declare a callback for the internalize pass that will ask for every // Declare a callback for the internalize pass that will ask for every
// candidate GlobalValue if it can be internalized or not. // candidate GlobalValue if it can be internalized or not.
SmallString<64> MangledName; SmallString<64> MangledName;
auto mustPreserveGV = [&](const GlobalValue &GV) -> bool { auto mustPreserveGV = [&](const GlobalValue &GV) -> bool {
// Unnamed globals can't be mangled, but they can't be preserved either.
if (!GV.hasName())
return false;
// Need to mangle the GV as the "MustPreserveSymbols" StringSet is filled // Need to mangle the GV as the "MustPreserveSymbols" StringSet is filled
// with the linker supplied name, which on Darwin includes a leading // with the linker supplied name, which on Darwin includes a leading
// underscore. // underscore.
MangledName.clear(); MangledName.clear();
MangledName.reserve(GV.getName().size() + 1); MangledName.reserve(GV.getName().size() + 1);
Mangler::getNameWithPrefix(MangledName, GV.getName(), Mangler::getNameWithPrefix(MangledName, GV.getName(),
MergedModule->getDataLayout()); MergedModule->getDataLayout());
return MustPreserveSymbols.count(MangledName); return MustPreserveSymbols.count(MangledName);
▲ Show 20 Lines • Show All 233 Lines • Show Last 20 Lines

test/LTO/X86/unnamed.ll

  • This file was added.
; RUN: llvm-as -o %t.bc %s
; RUN: llvm-lto -save-merged-module -o %t2 %t.bc
; RUN: llvm-dis -o - %t2.merged.bc | FileCheck %s
; CHECK-NOT: global i32
target triple = "x86_64-unknown-linux-gnu"
@0 = private global i32 42
@foo = constant i32* @0